We use ab initio density functional calculations to determine the structural and electronic properties of deuterium in bulk palladium. The focus of our study is the binding and the nearest-neighbor distance between D atoms in the very concentrated limit of a hypothetical ${\mathrm{PdD}}_2$ crystal. These results are compared to analogous calculations for bulk PdD and Pd. We find that even at very high D concentrations in the bulk, the equilibrium distance between two D atoms is increased by ≊0.2 Å from the gas value of 0.74 Å. This large internuclear distance makes a cold-fusion reaction of deuterium very improbable.

• Received 10 May 1989

DOI:https://doi.org/10.1103/PhysRevLett.63.59